摘要目的:探讨慢性进行性眼外肌麻痹(CPEO)的临床特点、骨骼肌病理表现和基因变异特点。方法:选择焦作市人民医院神经内科自1997年1月至2021年12月确诊的16例CPEO患者进入研究，收集患者起病年龄、病程等临床资料、肌肉病理检查结果并分析其基因变异特点。结果:16例患者首发症状均为上眼睑下垂，其中15例存在眼球运动障碍，6例存在复视，4例伴有近端肢体无力，3例伴吞咽困难和构音障碍。肌电图结果提示16例患者中肌源性损害7例，神经源性损害1例，肌源性合并神经源性损害1例，肌电图正常7例。骨骼肌活检结果显示14例患者可见破碎红边纤维(RRF)；11例存在细胞色素C氧化酶(COX)阴性肌纤维；3例有少量变性坏死肌纤维，伴单核吞噬细胞浸润。免疫组化染色提示有CD8和CD68阳性淋巴细胞浸润。10例行基因检测的患者结果显示，6例为线粒体DNA(mtDNA)单一大片段缺失，1例为mtDNA点突变，1例为核DNA(nDNA)点突变，2例未检测到明确与临床表型相关的致病性变异。5例行电镜检查的患者结果显示，4例可见肌膜下和肌原纤维间有异常线粒体聚集。结论:CPEO患者临床特征除上眼睑下垂和眼球运动障碍外，小部分患者可伴有吞咽困难和肢体无力。mtDNA单一大片段缺失是CPEO主要的突变形式。

abstractsObjective:To investigate the clinical characteristics, skeletal muscle pathologies and gene variations of chronic progressive external ophthalmoplegia (CPEO).Methods:Sixteen patients with conformed CPEO, admitted to our hospital from January 1997 to December 2021, were chosen. Their clinical data such as onset age and course of diseases and muscle pathological examination results were collected and their gene variation characteristics were analyzed.Results:The initial symptom in all 16 patients was ptosis of varying degrees; 15 patients were with eye movement disorder, 6 with diplopia, 4 with proximal limb weakness, and 3 with dysphagia and dysarthria. Among the 16 patients, electromyography showed myogenic damage in 7 patients, myogenic combined with neurogenic damage in 1 patient, neurogenic damage in 1 patient, and normal in 7 patients. Skeletal muscle biopsies indicated that 14 patients were with ragged red fibers (RRF), 11 patients had cytochrome C oxidase (COX)-negative muscle fibers, 3 patients had a small amount of degenerated and necrotic myofibers with mononuclear phagocytic infiltration. Immunohistochemical staining indicated infiltration of CD8 and CD68 positive lymphocytes. Ten patients accepted genetic test, indicating 6 patients with single large fragment deletion of mitochondrial DNA (mtDNA), 1 patient with mtDNA point mutation, 1 patient with nucleosomal DNA (nDNA) point mutation, and 2 patients without pathogenicity variation clearly associated with clinical phenotype. Electron microscopy in 5 patients showed that abnormal mitochondrial aggregation was noted in 4 patients under the sarcolemma and among the myofibrils.Conclusion:In addition to ptosis and eye movement disorders, a small number of patients with CPEO may be accompanied by dysphagia and limb weakness; and single large fragment deletion of mtDNA is the main mutation form of CPEO.